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Vintage RC Helicopters - Hirobo Sceadu

 HIROBO Sceadu

Hirobo Sceadu

Named after the mythological Celtic/Norse Goddess who carried a Bow and Arrows on her back and wore shining armour; twin sister to Freya.

Known as the Shuttle Sceadu, it was originally intended to replace the shuttle and thus was available in both '30' and '50' sizes.  However demand for the shuttle was such that the two ended up running concurrently though the Sceadu was mostly bought in the '50' size.

Sceadu 30-50 build manual  -  2001 version.    Sceadu 30-50 build manual addendum  -  2001 version.

Sceadu upgrades

Hirobo Sceadu Evolution

     EVO 50 early version          

After a couple of years the inevitable design update was carried out to incorporate a number of upgrades.  Because it was not a complete new model it was therefore called the 'Sceadu Evolution' and was available in two forms.  HPM being the originally mechanical pitch version with a rocking cradle and SWM; this was the upcoming ccpm control system that required a transmitter with electronic swashplate servo mixing to give both cyclic and pitch functions.  Again available in both '30' and '50' sizes though as before, predominantly bought as the '50' variant.


The frames were moulded of a tougher material adding strength and making them more rigid.  A third main-shaft bearing fitted below the main gear further stiffened the frames and give better support to the main shaft for more precise gear mesh during hard aerobatics.  The redesigned fuel tank held more fuel, and was secured between the frames by four rubber feet thus isolating it from vibration. Demanding aerobatics makes an engine work harder and generate more heat so to keep the engine happy  the cooling fan was improved to the increase the airflow over the engine's head.  Note that engine cooling was considered a weak spot on the initial version of the Sceadu.

Main Frame

bullet All new Main frame design with integrated, easy to access bearing blocks, integrated cooling shroud, .30 to.50 size engine mounting locations, easy glow plug access, provisions for routing tail servo wires from the back to the heli to the servo tray, and even a handy carburettor fuel "pinch off".
bullet New heavy duty, front electronics tray with encapsulated foam lined battery box!! No More Batteries coming loose in pirouettes!!!!!!
bullet New Integrated easily accessible switch mount capable of handling all switch sizes.
bullet Main Frame is capable of handling standard collective pitch controls or Hirobo's SWM (swash mode) 120 deg. CCPM system.
bullet A 10mm hollow main shaft is included to handle the stresses of rotor head loads on the main frame. Super strong, super light
bullet New larger Bearing are used to support the collective lever system for complete "slop" free smooth control for any flight envelope.

Drive Train

bullet New triple bearing supported clutch/clutch bell system to handle .30 to .50 class engines.
bullet New Fan/Flywheel assembly (starter pulley) for improved centring on engine crankshaft.
bullet Fan is factory drilled to accept magnet for a throttle governor.
bullet New drive train layout puts engine in front of main shaft for better overall CG balancing and allowing the gear reduction for the tail gearbox to happen at the main gear instead of a pulley arrangement.
bullet Accepts a DTDS (Direct Tail Drive System) option conversion set for tail drive authority under all conditions! Great for aerobatic autos.
bullet A belt driven tail utilizing a lower friction belt is standard equipment. an optional Torque tube pipe drive will be available separately as well.
bullet New larger pulleys allow stronger belt contact under the severest of conditions.
bullet All rotating shafts are dual ball bearing supported for smoothness.

FZ-III Rotor Head System

bullet 6mm solid axle with internal threads for securing the blade grips.
bullet Floating axle design with wide dampeners for extra support of the Feathering spindle.
bullet Thrust bearings are standard for smooth collective changes through the entire pitch range especially under the demanding loads of radical 3D flight.
bullet New heavier duty blade grips with a 4mm blade bolt are standard for the ultimate in reliability. Accepts 12mm root Main blades with 4mm bolt hole
bullet Head button for "palming" the rotor head is standard.
bullet The FZ-III Seesaw features adjustable Bell/Hiller ratios for all flight styles similar to ratios successfully used on the Freya.
bullet New stabilizer control arm strengthened for those unexpected "oops"
bullet Over 22 degrees usable collective pitch available
bullet Stabilizer Blades feature adjustable weights and are secured to the flybar with dual set screws. Same paddles included on the GPH346 and Shuttle RG

Main Blades

bullet For .30 Size Sceadu, 550mm new design factory assembled wood blades are included as standard equipment.
bullet For .50 Size Sceadu, 570 FRP (fibreglass) main blades are included as standard equipment.

Tail Rotor System

bullet Uses the successful Freya Double pin type tail pitch slider for precise tail control. Slider is dual ball bearing supported with "a" links to a ball joint on the tail blade holder.
bullet Each Tail Blade Holder uses a single thrust bearing and radial bearing for exact rotational movement.
bullet New aggressive super stiff tail blades are included as standard equipment for the 9 3/4 inch tail rotor disk. Super tail power for today's demanding gyros.
bullet Tail Boom Mounted Servo for tail control is standard equipment - Also available a 5mm control rod to replace the 2 mm existing rod.


bullet New higher capacity sealed muffler also included.

New Cabin design and materials

bullet New shaped cabin is sleek and fast like the Shuttle's Big Brother's, the Eagles.
bullet Made of durable impact resistant polypropylene. Blow moulded for smooth round Lines and definitely shock resistant.

Tail fins

bullet New larger shaped fins effective in fast forward flight when decals are applied or ideal for 3D flying with their decals removed.

Fuel tank

bullet New rear mount location with 4 point suspension in the main frame.
bullet New centralized stopper allows dependable clunk line freedom.
bullet Now 370 cc, increased 120 cc from the previous Shuttle Tank of 250 cc. Very transparent for easy fuel level checks.

Sceadu review - Review of early version by unknown reviewer

EVO 50 later version

A few minor changes were later made to the EVO; the rotor head was changed to the FZ-IV, featuring a machined aluminium centre block and had the flexibility to be configured to meet pilot's proficiency level. For example, the head featured an "auto-stability" configuration that made it a stable trainer however, moving a few control balls and changing their pick-up points made the helicopter a potent aerobatic performer.  Some other highlights of the Evolution were push-pull linkages, two-piece flybar paddles with adjustable weights and a longer-than-normal tail boom so 600mm-long main blades could be used.

Sceadu review - Review of later version (with OS Hyper 50 engine) by unknown reviewer

Sceadu Evo parts - Optional parts colour chart for the Evo.

Hirobo Sceadu Evolution Final versions

The helicopter was further developed finally into a 90 size version.  No info currently held on these later versions.

Hirobo Sceadu Evolution Documentation

Sceadu Evolution HPM build manual  -  2001 version.

Sceadu Evolution SWM build manual  -  2001 version - note that parts listings are missing.

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